1. Field of the Invention
The invention relates to an ureteral catheter which compresses the ureteral orifice at ureterovesical junction through the bladder at the time of cystoscopic examination and retrograde pyelogram. The purpose is to prevent the leakage of the injected iodinated contrast from the ureteral orifice back to the bladder cavity. It improves the quality of the retrograde pyelogram film and facilitates the efficiency of the procedure. From time to time, most practicing urologist have had experience with incomplete occlusion of the ureteral orifice with a cone tip ureteral catheter during the procedure of retrograde pyelography. As the result, the ureter cannot be sufficiently filled with pressure to distend the portion of the ureter or renal collecting system in question. This is especially true in patients with large patulous ureteral orifice or dilated intramural portion of ureter.
In contrast, in a situation when a patient has ureteral orifice too small to accomodate the conventional cone tip ureteral catheter or a segment of whistle tip, or spiral tip ureteral catheter, or in a situation when the distal ureter is angulated from the ureteral catheter, retrograde pylegraphy will be very difficult or impossible.
To overcome these difficulties, a compression shield, or a small occlusion plate is constructed at approximately half to two centimeters proximal to the tip of the ureteral catheter. The plate on the ureteral catheter is used to compress the bladder mucosa around the ureteral orifice. It prevents the leakage of the injected contrast back to the bladder cavity in a patulous ureteral orifice.
It provides a tight seal around a high pressure space and forces the contrast to flow into the ureter in a small or angulated ureteral orifice when it is difficult to cannulate.
2. Description of the Prior Art
Cystoscopic examination and retrograde pyelogram is a common urological procedure. It provides adequate visualization of the ureter. The procedure is usually performed to a patient in the following conditions:
1. When conventional intravenous pyelogram cannot sufficiently opacify or fill the ureter precluding an adequate diagnosis of the ureteral pathology. PA0 2. When patient has medical conditions not suitable the usage of intravenous injection of iodinated contrast. This includes patient with previous history of iodinated contrast allergy, azotemia, multiple myeloma, etc. PA0 3. To identify the fistula, calculus, tumor, or structural abnormality of the ureter.
Most retrograde pyelography can be adequately performed with the conventional ureteral catheters available to date. The ureteral catheters with whistle tip, flexible whistle tip, cone tip, spiral tip, olive tip is commonly used. When using these catheters there are however significant leakage of the contrast from the ureter to the bladder cavity as the ureter is not tightly occluded by these catheters rendering the procedure inefficient, difficult and time consuming. When the ureter is poorly or inadequately filled in the areas in question, the procedures have to be repeated and a X-ray be taken. It therefore increases the chance of excessive radiation exposure to patient, operator and the nurses. There has been no catheter that can occlude the ureteral orifice by compressing the bladder mucosa around the ureteral orifice available to date.